Cerato-platanin elicits transcription of defence-related genes earlier than Ceratocystis platani on Platanus acerifolia

The ascomycete Ceratocystis platani (Walter) Engelbrecht & Harrington is the causal agent of canker stain, the most dangerous disease affecting the plane tree. Cerato-platanin (CP) is a protein elicitor from C. platani that acts as a pathogen-associated molecular pattern (PAMP), eliciting defence responses in both host and non-host plants. Using plane leaves as an experimental model, we compared the capacity of CP and C. platani to cause alterations in the transcription level of five Platanus acerifolia (Ait.) Willd. genes, three strictly related to a defence response, and two non-defence related. The results suggest that CP elicits the transcription of defence-related genes earlier than does C. platani. The expression of the cp gene in C. platani inoculated on plane leaves and grown in an axenic culture was also studied. For the first time CP has been shown to be released by C. platani when inoculated on P. acerifolia. The cp gene was expressed sooner when C. platani was inoculated on the leaves, than when it was grown in axenic culture, suggesting that the host-tree has a positive effect on the expression of this elicitor protein.